Methods of drying reactor systems

Abstract

Methods for heating reactor systems include passing a gaseous fluid to a regenerator at a first flow rate and passing a first portion of the gaseous fluid present in the regenerator to a reactor at a second flow rate from 50% to 80% of the first flow rate. The methods include passing a first portion of the gaseous fluid present in the reactor out of the reactor in a reactor outflow stream, passing a first portion of the reactor outflow stream back to the reactor, and passing a second portion of the reactor outflow stream out of the reactor system at a third flow rate from 10% to 50% of the first flow rate. The methods include passing a second portion of the gaseous fluid present in the reactor out of the reactor system at a fourth flow rate from 10% to 50% of the first flow rate. A temperature of the gaseous fluid passed to the regenerator is increased, over a time period, by greater than or equal to 100 °C.

Description

METHODS FOR DRYING REACTOR SYSTEMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 609,905 filed December 14, 2023, the contents of which are incorporated in their entirety herein.TECHNICAL FIELD

[0002] Embodiments described herein generally relate to chemical processing and, more specifically, to methods for drying reactor systems.BACKGROUND

[0003] Light olefins may be utilized as base materials to produce many types of goods and materials. Thus, there is an industry demand for light olefins, such as ethylene, propylene, and butene. Light olefins may be produced by different reaction processes depending on the given chemical feed stream, which may be a product stream from a crude oil refining operation. Many light olefins may be produced through processes employing particulate solids, such as solid particulate catalysts.SUMMARY

[0004] Reactor systems for producing light olefins may be shut down for a variety of reasons, such as performing maintenance. Starting up a reactor system may include heating the reactor system prior to loading particulate solids into the reactor system and reacting a chemical feed stream to form products, such as light olefins. Heating the reactor system may dry out system components, such as refractory lining in various components of the reactor system, such as pressure vessels and transfer lines. In some embodiments, heating and drying the refractory lining may enhance the reliability of the refractory lining for protecting metallic components of the reactor system, such as pressure vessels and transfer lines, from hot particulate solids and gasses during the reaction of chemical feedstocks to form products. However, uneven heating between components of the reactor system may induce mechanical stress on the components of the reactor system. Embodiments, of methods for heating reactor systems described herein may include directing a gaseous fluid through the reactor system. The gaseous fluid may be passed to theregenerator at a first flow rate, and then from the regenerator to the reactor at a second flow rate that is from 50% to 80% of the first flow rate. The temperature of the gaseous fluid may be increased, over a period of time, by greater than or equal to 100 °C, to heat the reactor system. The flow rate and the temperature of the gaseous fluid may be controlled to heat the reactor system in a relatively even manner to dry refractory material lining in the reactor system.

[0005] According to one or more embodiments disclosed herein, a method for drying a reactor system comprising a reactor and a regenerator comprises passing a gaseous fluid to the regenerator at a first flow rate and passing a first portion of the gaseous fluid present in the regenerator to the reactor at a second flow rate. The second flow rate is from 50% to 80% of the first flow rate. The method comprises passing a first portion of the gaseous fluid present in the reactor out of the reactor in a reactor outflow stream, passing a first portion of the reactor outflow stream back to the reactor, and passing a second portion of the reactor outflow stream out of the reactor system at a third flow rate. The third flow rate is from 10% to 50% of the first flow rate. The method comprises passing a second portion of the gaseous fluid present in the reactor out of the reactor system at a fourth flow rate. The fourth flow rate is from 10% to 50% of the first flow rate. A temperature of the gaseous fluid passed to the regenerator is increased, over a time period, by greater than or equal to 100 °C.

[0006] Additional features and advantages of the technology disclosed herein will be set forth in the detailed description that follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the technology as described herein, including the detailed description that follows, the claims, as well as the appended drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0008] FIG. 1 schematically depicts a reactor system, according to one or more embodiments disclosed herein; and

[0009] FIG. 2 schematically depicts another reactor system, according to one or more embodiments disclosed herein.

[0010] It should be understood that the drawings are schematic in nature, and do not include some components of a fluid catalytic reactor system commonly employed in the art, such as, without limitation, temperature transmitters, pressure transmitters, flow meters, pumps, valves, and the like. It would be known that these components are within the spirit and scope of the present embodiments disclosed. However, operational components, such as those described in the present disclosure, may be added to the embodiments described in this disclosure. Reference will now be made in greater detail to various embodiments, some embodiments of which are illustrated in the accompanying drawings.DETAILED DESCRIPTION

[0011] One or more non-limiting embodiments of methods for heating reactor systems are described herein, which according to one or more embodiments may dry out refractory materials located within the reactor systems. When described herein, heating may be referred to as drying in the context of systems that include refractory materials that are not dry upon start of the processes described herein. FIG. 1 depicts an embodiment of a reactor system 100. Embodiments of the methods for heating reactor systems described herein may be performed on reactor systems such as the reactor system 100 depicted in FIG. 1. However, it should be understood that the methods for drying reactor systems described herein are not necessarily limited to the use on the reactor system 100 depicted in FIG. 1.

[0012] Referring now to FIG. 1, a reactor system 100 may comprise a reactor 5 and a regenerator 10. During steady-state operation, a feed chemical may be reacted by contact with a particulate solid, such as a catalyst, in reactor 5. The particulate solid may be separated from the reaction products and passed to the regenerator 10. In the regenerator 10, the particulate solid may be regenerated by heating and / or removal of coke. Such regenerated particulate solid may be passed back to the reactor 5 for subsequent cycles of the reaction.

[0013] In non-limiting examples, the reactor system 100 described herein may be utilized to produce light olefins from hydrocarbon feed streams. Light olefins may be produced from a variety of hydrocarbon feed streams by utilizing different reaction mechanisms. For example, light olefins may be produced by at least dehydrogenation reactions, cracking reactions, dehydration reactions, and methanol-to-olefin reactions. These reaction types may utilize different feed streams and different particulate solids to produce light olefins. It should be understood that when“catalysts” are referred to herein, they may equally refer to the particulate solid referenced with respect to the system of FIG. 1. In one or more embodiments, the reactor system 100 described herein may be utilized to produce light olefins by a dehydrogenation reaction. Examples of methods for dehydrogenating hydrocarbons are described in and International Patent Publication WO 2020 / 046978, entitled “Methods for Dehydrogenating Hydrocarbons,” and International Patent Publication WO 2016 / 160273, entitled “Integrated C3-C4 Hydrocarbon Dehydrogenation Process,” the teachings of each of which are incorporated by reference in their entirety herein.

[0014] Still referring to FIG. 1, the reactor system 100 generally comprises multiple system components, such as a reactor 5 and a regenerator 10. As used herein in the context of FIG. 1, a reactor 5 generally refers to the portion of a reactor system 100 in which the major process reaction takes place, and the particulate solids are separated from the product stream of the reaction. In one or more embodiments, the particulate solids may be spent, meaning that they are at least partially deactivated. Also, as used herein, a regenerator 10 generally refers to the portion of a reactor system 100 where the particulate solids are regenerated, such as through combustion, and the regenerated particulate solids are separated from the other process material, such as evolved gasses from the combusted material previously on the spent particulate solids or from supplemental fuel. Generally, the reactor 5 may be in fluid communication with the regenerator 10. For example, particulate solid transfer line 32 fluidly connect the reactor 5 and the regenerator 10 such that at least partially spent particulate solids may be passed from the reactor 5 to the regenerator 10, and transfer line 31 may fluidly connect the reactor 5 and the regenerator 10 such that regenerated particulate solids may be passed from the regenerator 10 to the reactor 5.

[0015] In one or more embodiments, transfer lines may be connected to the reactor 5, or the regenerator 10, or both the reactor 5 and the regenerator 10. In general, transfer lines may be signified by arrows in the figures. The transfer lines may be any suitable shape, and in one or more embodiments, the transfer lines may be pipes. In one or more embodiments, a reactor feed line 60 may be connected to the reactor 5. The reactor feed line 60 may be suitable for passing a feed chemical to the reactor 5. In one or more embodiments, reactor effluent line 40 may be connected to the reactor 5. Reactor effluent line 40 may be suitable for passing reaction products from the reactor 5. In one or more embodiments, particulate solid recycle line 33 may be connected to the reactor 5. Particulate solid recycle line 33 may be suitable for recycling particulate solids in the reactor 5. In one or more embodiments, particulate solid transfer line 32 may be connected to boththe reactor 5 and the regenerator 10. Particulate solid transfer line 32 may be suitable for passing at least partially spent particulate solids from the reactor 5 to the regenerator 10. In one or more embodiments, particulate solid transfer line 31 may be connected to both the reactor 5 and the regenerator 10. Particulate solid transfer line 31 may be suitable for passing regenerated catalyst from the regenerator 10 to the reactor 5. In one or more embodiments, particulate solid recycle line 34 may be connected to the regenerator 10. Particulate solid recycle line 34 may be suitable for recycling particulate solids in the regenerator 10. In one or more embodiments, regenerator effluent line 25 may be connected to the regenerator 10. Regenerator effluent line 25 may be suitable for passing one or more gasses from the regenerator. In one or more embodiments, regenerator gas feed line 55 may be connected to the regenerator 10. Regenerator gas feed line 55 may be suitable for passing one or more gasses to the regenerator 10.

[0016] In one or more embodiments, various transfer lines may comprise one or more valves. The valves may be any suitable valve for controlling the flow of fluids and solids through each of the transfer lines. For example, in some embodiments, one or more of the transfer lines may comprise slide valves. However, it should be noted that the type of valve in each transfer line is not necessarily limited.

[0017] In one or more embodiments, one or more system components of the reactor system 100 may comprise a refractory lining. The refractory lining may be positioned inside at least portions of the reactor 5, the regenerator 10, and one or more of the transfer lines, including but not limited to particulate solid transfer line 31 and particulate solid transfer line 32. Without intending to be bound by theory, the refractory lining may allow for the transport of hot particulate solids and gasses through the reactor system 100 without damaging the outer shell of the vessels and transfer lines included in the reactor system 100.

[0018] After a period of time during which the reactor system 100 is shut down, the reactor system may be heated, drying the refractory lining, prior to loading particulate solids, such as catalyst, and chemical feedstocks into the reactor to begin the reaction process. Heating and drying the system components of the reactor system 100 in a gradual, controlled manner may reduce mechanical stress on the system components of the reactor system 100 during the heating process. Additionally, heating and drying the refractory material may gradually remove water from the refractory material. For example, the reactor system 100 may be heated at a rate from about 5°C / hr to about 50 °C / hr until the reactor reaches a temperature from about 200 °C to about 400 °C, such that water may be removed from the refractory lining. Without intending to be bound by theory, water in the refractory material may damage the refractory material if the refractory material is heated too quickly. Such damage may reduce the effectiveness of the refractory material for protecting the outer shells of the vessels and transfer lines of the reactor system 100.

[0019] Embodiments of the methods for heating a reactor system are now described in greater detail. Generally, in embodiments of the method for heating a reactor system described herein, a gaseous fluid may be passed through the regenerator 10 and the reactor 5. The gaseous fluid may be heated over a period of time, such that the temperature of the regenerator 10, the reactor 5, and other components of the reactor system 100 increases, heating and drying system components of the reactor system 100. For example, the temperature of reactor 5 and regenerator 10 may each increase at a rate of about 5 °C / hr to about 50 °C / hr until the reactor reaches a temperature of about 200 °C to about 400 °C. The temperature of the gaseous fluid may be steadily increased over time, or increased by steps, such that there is generally a monotonic heating in the regenerator 10.

[0020] In one or more embodiments, a method for heating a reactor system may comprise passing a gaseous fluid to the regenerator 10 at a first flow rate. The first flow rate may be a mass flow rate. The first flow rate is not necessarily limited and may depend, at least in part, on the size of the reactor 5 and the regenerator 10. Referring to FIG. 1, the gaseous fluid may be passed to the regenerator 10 through regenerator gas feed line 55. The gaseous fluid may be any suitable gas or mixture of gasses. In one or more embodiments, the gaseous fluid may comprise at least nitrogen, oxygen, or both. In one or more embodiments, the gaseous fluid may comprise air. For example, the gaseous fluid may comprise at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.%, at least 95 wt.% air, or even at least 99 wt.% air.

[0021] Still referring to FIG. 1, in one or more embodiments, a method for heating a reactor system may comprise passing first portion of the gaseous fluid present in the regenerator 10 to the reactor 5. The first portion of the gaseous fluid present in the regenerator 10 may be passed to the reactor 5 through particulate solid transfer line 31, particulate solid transfer line 32, or both particulate solid transfer line 31 and particulate solid transfer line 32.

[0022] In one or more embodiments, the first portion of the gaseous fluid present in the regenerator 10 may be passed to the reactor 5 at a second flow rate. The second flow rate may be from 50% to 80% of the first flow rate. For example, the second flow rate may be from 50% to 80%, from 55% to 80%, from 60% to 80%, from 65% to 80%, from 70% to 80%, from 75% to 80%, from 50% to 75%, from 50% to 70%, from 50% to 65%, from 50% to 60%, or from 50% to 55%, of the first flow rate, or any range or combination of ranges formed from these endpoints. In one or more embodiments, the second flow rate may be controlled such that the rate at which the regenerator 10 and the reactor 5 are heated is relatively even and the temperature difference between the regenerator 10 and the reactor 5 is less than 100 °C. This may help reduce stress imparted onto system components due to differences in thermal expansion between the reactor 5 and the regenerator 10.

[0023] In one or more embodiments, the second flow rate may be controlled by at least partially opening or at least partially closing one or more valves in particulate solid transfer line 31 and by least partially opening or at least partially closing one or more valves in particulate solid transfer line 32. For example, particulate solid transfer line 31 may include one or more valves, such as a slide valve. In one or more embodiments, valve 131 in particulate solid transfer line 31 may be at least partially opened to increase the second flow rate. In one or more embodiments, slide valve 131 may be at least partially closed to decrease the second flow rate. In one or more embodiments, particulate solid transfer line 32 may include one or more valves, such as a slide valve. In one or more embodiments, valve 132 in particulate solid transfer line 32 may be at least partially closed to decrease the second flow rate. In one or more embodiments valve 132 may be at least partially opened to increase the second flow rate. One or more embodiments of the method described herein may comprise at least partially opening or at least partially closing one or more valves such that the second flow rate is from 50% to 80% of the first flow rate. In one or more embodiments, particulate solid transfer line 32 and particulate solid transfer line 31 may comprise refractory lining. Passing the gaseous fluid through particulate solid transfer line 32 and particulate solid transfer line 31 may dry the refractory lining and may heat particulate solid transfer line 32 and particulate solid transfer line 31.

[0024] Still referring to FIG. 1 , in one or more embodiments, at least a portion of the gaseous fluid in the regenerator 10 may be passed through particulate solid recycle line 34. Particulate solid recycle line 34 may comprise a refractory material lining and passing at least a portion ofthe gaseous fluid in the regenerator 10 through particulate solid recycle line 34 may dry the refractory lining in particulate solid recycle line 34. The flow rate of the gaseous fluid passing through particulate solid recycle line 34 may be controlled by at least partially opening or at least partially closing a valve in particulate solid recycle line 34.

[0025] In one or more embodiments, a method for heating a reactor system may comprise passing a first portion of the gaseous fluid present in the reactor 5 out of the reactor 5 in a reactor outflow stream. In one or more embodiments, the reactor outflow stream may be passed through the reactor effluent line 40. The reactor effluent line 40 may comprise a refractory material lining and passing the first portion of the gaseous fluid present in the reactor 5 through the reactor effluent line may heat and dry the reactor effluent line 40.

[0026] In one or more embodiments, at least a portion of the gaseous fluid in the reactor 5 may be passed through particulate solid recycle line 33. Particulate solid recycle line 33 may comprise a refractory material lining and passing at least a portion of the gaseous fluid in the reactor 5 through particulate solid recycle line 33 may dry the refractory lining in particulate solid recycle line 33. The flow rate of the gaseous fluid passing through particulate solid recycle line 33 may be controlled by at least partially opening or at least partially closing a valve in particulate solid recycle line 33.

[0027] Still referring to FIG. 1, in one or more embodiments, at least a portion of the reactor outflow stream may be passed through reactor effluent line 40 to a compressor 15. The compressor 15 may be any suitable compressor. In one or more embodiments, the compressor 15 may increase the pressure of the gaseous fluid passed through the compressor 15. In one or more embodiments, the compressor 15 may be used to circulate at least a portion of the gaseous fluid from the reactor 5 through the reactor effluent line 40 and back to the reactor 5 through reactor feed line 60.

[0028] In one or more embodiments, the reactor outflow stream may be separated to form the first portion of the reactor outflow stream and the second portion of the reactor outflow stream downstream of the compressor 15. In one or more embodiments, a method for drying a reactor system may comprise passing the first portion of the reactor outflow stream back to the reactor 5. In one or more embodiments, the first portion of the reactor outflow stream may be passed back to the reactor through reactor feed line 60. The reactor feed line 60 may comprise a refractorymaterial lining and passing the first portion of the reactor outflow stream through the reactor feed line 60 may dry the reactor feed line 60.

[0029] According to one or more embodiments, a method for drying a reactor system may comprise passing a second portion of the reactor outflow stream 40 out of the reactor system 100 at a third flow rate. In one or more embodiments, the third flow rate may be from 10% to 50% of the first flow rate. For example, the third flow rate may be from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, from 30% to 50%, from 35% to 50%, from 40% to 50%, from 45% to 50%, from 10% to 45%, from 10% to 40%, from 10% to 35%, from 10% to 30%, from 10% to 25%, from 10% to 20%, or from 10% to 15% of the first flow rate, or any range or combination of ranges formed from these endpoints. In some embodiments, the third flow rate may be from 20% to 45% of the first flow rate.

[0030] The second portion of the reactor outflow stream may be passed out of the reactor system 100 through transfer line 35. In one or more embodiments transfer line 35 may be open to the atmosphere, as a vent. Still referring to FIG. 1, transfer line 35 may be positioned downstream of compressor 15. In such embodiments, the second portion of the reactor outflow stream may be passed through the compressor 15 before leaving the reactor system 100. In some embodiments, not depicted, line 35 may be positioned upstream of compressor 15. In such embodiments, the second portion of the reactor outflow stream is not passed through the compressor 15.

[0031] In one or more embodiments, the third flow rate may be controlled by at least partially opening or at least partially closing one or more valves in transfer line 35. For example, the third flow rate may be increased by at least partially opening valve 135 in transfer line 35 and the third flow rate may be decreased by at least partially closing valve 135 in transfer line 35. One or more embodiments of the methods described herein may comprise at least partially opening or at least partially closing one or more valves such that the third flow rate is from 10% to 50% of the first flow rate. Controlling the third flow rate may control the rate at which the reactor 5 is heated and the third flow rate may be controlled to maintain relatively even rate of heating between the reactor 5 and the regenerator 10 such that the temperature difference between the regenerator 10 and the reactor 5 is less than 100 °C.

[0032] According to one or more embodiments, a method for drying a reactor system may comprise passing a second portion of the gaseous fluid present in the reactor 5 out of the reactorsystem 100 at a fourth flow rate. The second portion of the gaseous fluid present in the reactor 5 may be passed out of the reactor system through transfer line 45. In one or more embodiments, the transfer line 45 may open to the atmosphere, as vent. In one or more embodiments, the fourth flow rate may be from 10% to 50% of the first flow rate. For example, the fourth flow rate may be from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, from 30% to 50%, from 35% to 50%, from 40% to 50%, from 45% to 50%, from 10% to 45%, from 10% to 40%, from 10% to 35%, from 10% to 30%, from 10% to 25%, from 10% to 20%, or from 10% to 15% of the first flow rate, or any range or combination of ranges formed from these endpoints.

[0033] In one or more embodiments, the fourth flow rate may be controlled by at least partially opening or at least partially closing one or more valves in transfer line 45. For example, the fourth flow rate may be increased by at least partially opening valve 145 in transfer line 45 and the fourth flow rate may be decreased by at least partially closing valve 145 in transfer line 45. One or more embodiments of the methods described herein may comprise at least partially opening or at least partially closing one or more valves such that the fourth flow rate is from 10% to 50% of the first flow rate. The fourth flow rate may be controlled to maintain a relatively even rate of heating between the reactor 5 and the regenerator 10. For example, controlling the fourth flow rate may help keep the temperature of the reactor 5 within 100 °C of the temperature of the regenerator 10. This may reduce stress imparted onto system components due to differences in thermal expansion between the reactor 5 and the regenerator 10.

[0034] In one or more embodiments, a temperature of the gaseous fluid passed to the regenerator 10 may be increased, over a time period, by greater than or equal to 100 °C. For example, the temperature of the gaseous fluid passed to the regenerator may be increased, over a time period, by greater than or equal to 100 °C, 125 °C, 150 °C, 175 °C, 200 °C, 225 °C, 250 °C, 275 °C, or even 300 °C. It should be noted that the time period is not necessarily limited. In one or more embodiments, the time period may be any suitable time period for heating the gaseous fluid such that the temperature of the reactor 5 and the regenerator 10 increase at a desired rate to a desired temperature.

[0035] The gaseous fluid may be heated by any suitable means. In one or more embodiments, the gaseous fluid may be heated in heater 21. Referring still to FIG. 1, the gaseous fluid may be passed to heater 21 through transfer line 20. The heater 21 may heat the gaseousfluid, and the heated gaseous fluid may be passed to the regenerator 10 through regenerator gas feed line 55. The heater 21 may be any heater suitable for heating the gaseous fluid. For example, the heater may be a fired heater or an electric heater. In one or more embodiments, the heater 21 is a fired heater. The fired heater may burn any suitable fuel source.

[0036] Without intending to be bound by theory, heating the gaseous fluid being passed to the regenerator 10, which is subsequently passed through the regenerator and the reactor, as previously described, may cause the regenerator 10 and the reactor 5 to be heated. Specifically, increasing the temperature of the gaseous fluid over a period of time and passing the heated gaseous fluid through the reactor system may cause the temperature of the regenerator to increase and may cause the temperature of the reactor to increase. Furthermore, passing the gaseous fluid through the one or more transfer lines connected to the reactor or the regenerator or both may heat the one or more transfer lines.

[0037] In one or more embodiments, a temperature of the regenerator 10 may increase at a rate of 5 °C / hr to 50 °C / hr. For example, a temperature of the regenerator 10 may increase at a rate of 5 °C / hr to 50 °C / hr, 10 °C / hr to 50 °C / hr, 15 °C / hr to 50 °C / hr, 20 °C / hr to 50 °C / hr, 25 °C / hr to 50 °C / hr, 30 °C / hr to 50 °C / hr, 35 °C / hr to 50 °C / hr, 40 °C / hr to 50 °C / hr, 45 °C / hr to 50 °C / hr, 5 °C / hr to 45 °C / hr, 5 °C / hr to 40 °C / hr, 5 °C / hr to 35 °C / hr, 5 °C / hr to 30 °C / hr, 5 °C / hr to 25 °C / hr, 5 °C / hr to 20 °C / hr, 5 °C / hr to 15 °C / hr, 5 °C / hr to 10 °C / hr, or any range or combination of ranges formed from these endpoints. The rate of change of temperature in the regenerator 10 may be determined by measuring the temperature within the regenerator 10 over a period of time. The temperature of the regenerator 10 may be measured by any suitable means. For example, the temperature of the regenerator 10 may be measured by thermocouples installed within the regenerator 10.

[0038] In one or more embodiments, a temperature of the reactor 5 may increase at a rate of 5 °C / hr to 50 °C / hr. For example, a temperature of the reactor 5 may increase at a rate of 5 °C / hr to 50 °C / hr, 10 °C / hr to 50 °C / hr, 15 °C / hr to 50 °C / hr, 20 °C / hr to 50 °C / hr, 25 °C / hr to 50 °C / hr, 30 °C / hr to 50 °C / hr, 35 °C / hr to 50 °C / hr, 40 °C / hr to 50 °C / hr, 45 °C / hr to 50 °C / hr, 5 °C / hr to 45 °C / hr, 5 °C / hr to 40 °C / hr, 5 °C / hr to 35 °C / hr, 5 °C / hr to 30 °C / hr, 5 °C / hr to 25 °C / hr, 5 °C / hr to 20 °C / hr, 5 °C / hr to 15 °C / hr, 5 °C / hr to 10 °C / hr, or any range or combination of ranges formed from these endpoints. The rate of change of temperature in the reactor 5 may be determined bymeasuring the temperature within the reactor 5 over a period of time. The temperature of the reactor may be measured by any suitable means. For example, the temperature of the reactor 5 may be measured by thermocouples installed within the regenerator 10.

[0039] Without intending to be bound by theory, increasing the temperature of the components of the reactor system 100, including the reactor 5, the regenerator 10, and the transfer lines, at a rate from 5 °C / hr to 50 °C / hr may allow the refractory lining to be heated and dried without causing damage to the refractory lining. The target for the rate of heating may depend at least in part on the specific refractory lining used in the reactor system.

[0040] In one or more embodiments, a temperature of the regenerator 10 does not exceed a temperature of the reactor 5 by greater than or equal to 100 °C. For example, a temperature of the regenerator 10 may not exceed the temperature of the reactor 5 by greater than or equal to 100 °C, greater than or equal to 90 °C, greater than or equal to 80 °C, or even greater than or equal to 70 °C. As described herein, the temperature of the regenerator 10 may not exceed the temperature of the reactor by greater than or equal to 100 °C at the same point in time during the drying process.

[0041] The temperature of the reactor 5 and the regenerator 10 may be measured by any suitable means. For example, the temperature of the reactor 5 may be measured by one or more temperature sensors, such as thermocouples, positioned in the reactor 5. In one or more embodiments, the one or more temperature sensors may be positioned to monitor temperature within the reactor vessel, where the reaction takes place during operation of the reactor. Fikewise, for example, the temperature of the regenerator 10 may be measured by one or more temperature sensors, such as thermocouples, positioned in the regenerator 10. In one or more embodiments, the one or more temperature sensors may be positioned to monitor temperature within the regenerator vessel. Other temperature sensors may be positioned throughout the reactor system 100 to monitor the temperature of the various components of the reactor system 100.

[0042] Without intending to be bound by theory, the temperature of the reactor 5 and the regenerator 10 should be kept relatively close (i.e., within 100 °C) to prevent stress on the transfer lines that connect the reactor 5 and the regenerator 10. As the reactor 5 and the regenerator 10 are heated, the reactor and the regenerator, and the transfer lines connected to the reactor 5 and the regenerator 10 may undergo thermal expansion. If the temperature difference between the reactor 5 and the regenerator 10 becomes too great, then differences in thermal expansion between thereactor 5 and the regenerator 10 may cause stress on the transfer lines or other system components in the reactor system 100.

[0043] In one or more embodiments, a superficial velocity of the gaseous fluid passing through the reactor may be greater than or equal to 1 ft / s. For example, the superficial velocity of the gaseous fluid passing through the reactor 5 may be greater than or equal to 1 ft / s, 1.25 ft / s, 1.5 ft / s, 1.75 ft / s, 2 ft / s, 2.25 ft / s, 2.5 ft / s, 2.75 ft / s, or even 3 ft / s. As described herein, “superficial velocity” refers to the velocity at which an individual phase flows through a given cross-sectional area. The bulk flow of a phase may be used to determine the superficial velocity of that phase. It should be noted that, individual particles or molecules within a phase may move in a different direction from, or even opposite to, the bulk flow of a phase without affecting the direction of the superficial velocity of that phase. Without intending to be bound by theory, when the superficial velocity of the gaseous fluid passing through the reactor is greater than or equal to 1 ft / s, then the gaseous fluid passing through the reactor may have a sufficient velocity to fluidize particulate solids, such as catalyst, that may be introduced into the reactor, one the reactor reaches a desired temperature.

[0044] According to one or more embodiments, a second portion of the gaseous fluid present in the regenerator 10 may be passed out of the reactor system 100. The second portion of the gaseous fluid present in the regenerator 10 may be passed out of the reactor system 100 at a fifth flow rate. In one or more embodiments, the fifth flow rate may be from 10% to 50% of the first flow rate. For example, the fifth flow rate may be from 10% to 50%, from 15% to 50%, from 20% to 50%, from 25% to 50%, from 30% to 50%, from 35% to 50%, from 40% to 50%, from 45% to 50%, from 10% to 45%, from 10% to 40%, from 10% to 35%, from 10% to 30%, from 10% to 25%, from 10% to 20%, or from 10% to 15% of the first flow rate, or any range or combination of ranges formed from these endpoints. In one or more embodiments, the second portion of the gaseous fluid present in the regenerator 10 may be passed out of the reactor system through regenerator effluent line 25.

[0045] In one or more embodiments, the fifth flow rate may be controlled by at least partially opening or at least partially closing one or more valves in regenerator effluent line 25. For example, the fifth flow rate may be increased by at least partially opening valve 125 in regenerator effluent line 25 and the fifth flow rate may be decreased by at least partially closing valve 125 inregenerator effluent line 25. One or more embodiments of the methods described herein may comprise at least partially opening or at least partially closing one or more valves such that the fifth flow rate is from 10% to 50% of the first flow rate.

[0046] Referring now to FIG. 2, in one or more embodiments, the reactor system 100 may further comprise a reactor side heat exchanger 6 and a regenerator side heat exchanger 11. The reactor side heat exchanger 6 may be used to heat chemical feedstocks being passed to the reactor 5. For example, a chemical feedstock may be passed to the reactor side heat exchanger through transfer line 50. The chemical feedstock may be heated in the reactor side heat exchanger 6 and the heated chemical feedstock may be passed from the reactor side heat exchanger 6 to the reactor 5 through reactor feed line 60. The chemical feedstock may be heated in reactor side heat exchanger 6 by thermal contact with the product stream exiting the reactor through reactor effluent line 40. The reactor side heat exchanger 6 may be any suitable gas / gas heat exchanger, including but not limited to a shell and tube heat exchanger. In one or more embodiments, the reactor side heat exchanger 6 may comprise refractory lining on at least a portion of an inside surface of the heat exchanger.

[0047] The regenerator side heat exchanger 11 may be used to cool gasses exiting the regenerator 10 through regenerator effluent line 25. The gasses exiting the regenerator 10 through regenerator effluent line 25 may be cooled in regenerator side heat exchanger 11 by contact with one or more gasses being passed to the regenerator 10. For example, a portion of the gasses being passed to the regenerator 10 may be thermally contacted with the gasses being passed from the regenerator 10 through regenerator effluent line 25 in the regenerator side heat exchanger 11 to cool the gasses being passed out of the regenerator 10. The regenerator side heat exchanger 11 may be any suitable gas / gas heat exchanger, including but not limited to a shell and tube heat exchanger. In one or more embodiments, the regenerator side heat exchanger 11 may comprise refractory lining on at least a portion of an inside surface of the heat exchanger.

[0048] One or more embodiments for drying reactor systems 100 described herein may include drying the reactor side heat exchanger 6, the regenerator side heat exchanger 11, or both the reactor side heat exchanger 6 and the regenerator side heat exchanger 11. Such embodiments are now described in more detail.

[0049] In one or more embodiments, at least a portion of the reactor outflow stream may be passed through the reactor side heat exchanger 6. For example, the reactor outflow stream may be passed from the reactor 6, through reactor effluent line 40 to the reactor side heat exchanger 6. In one or more embodiments, the reactor outflow stream may be passed through the reactor side heat exchanger 6 and then passed to the compressor 15 through transfer line 41. In one or more embodiments, the first portion of the reactor outflow stream may be passed to the reactor side heat exchanger 6 through transfer line 50. The first portion of the reactor outflow stream may then be passed from the reactor side heat exchanger 6 to the reactor 5 through reactor feed line 60. In one or more embodiments, passing the reactor outflow stream and the first portion of the rector outflow stream through the reactor side heat exchanger 6 may increase a temperature of the reactor side heat exchanger 6 and may dry refractory material included in the reactor side heat exchanger 6.

[0050] According to one or more embodiments, the second portion of the gaseous fluid present in the regenerator 10 may be passed through the regenerator side heat exchanger 11. For example, the second portion of the gaseous fluid present in the regenerator 10 may be passed to the regenerator side heat exchanger 11 through regenerator effluent line 25. The second portion of the gaseous fluid present in the regenerator 10 may then be passed from the regenerator side heat exchanger 11 through transfer line 27. In one or more embodiments, passing the second portion of the gaseous fluid present in the regenerator 10 through the regenerator side heat exchanger 11 may increase a temperature of the regenerator side heat exchanger 11 and may dry refractory material included in the regenerator side heat exchanger 11.

[0051] In one or more embodiments, the second portion of the gaseous fluid present in the regenerator 10 may be used to at least partially heat the gaseous fluid being passed to the regenerator 10. For example, a first portion of the gaseous fluid may be passed to the heater 21 through transfer line 22 and a second portion of the gaseous fluid may be passed to the regenerator side heat exchanger 11 through transfer line 24. A temperature of the second portion of the gaseous fluid may be increased in the regenerator side heat exchanger 11 through heat exchange with the second portion of the gaseous fluid in the regenerator 10 being passed through the regenerator side heat exchanger 11. The heated second portion of the gaseous fluid may be passed from the regenerator side heat exchanger through transfer line 26. The heated second portion of the gaseous fluid may be combined with the first portion of the gaseous fluid heated in heater 21 and the gaseous fluid may be passed to the regenerator 10 through regenerator feed line 55.

[0052] According to one or more embodiments, the drying process may be performed until the reactor 5 reaches a target temperature. In one or more embodiments, the target temperature of the reactor may be from 200 °C to 400 °C. For example, the target temperature of the reactor may be from 200 °C to 400 °C, from 220 °C to 400 °C, from 240 °C to 400 °C, from 260 °C to 400 °C, from 280 °C to 400 °C, from 300 °C to 400 °C, from 320 °C to 400 °C, from 340 °C to 400°C, from 360 °C to 400 °C, from 380 °C to 400 °C, from 200 °C to 390 °C, from 200 °C to 370°C, from 200 °C to 350 °C, from 200 °C to 330 °C, from 200 °C to 310 °C, from 200 °C to 290°C, from 200 °C to 270 °C, from 200 °C to 250 °C, from 200 °C to 230 °C, from 200 °C to 210°C, or any range or combination of ranges formed from these endpoints. It should be noted that the target temperature of the reactor may vary depending on the particular refractory material lining the reactor, the materials of construction used in the outer shell of the reactor vessel, and the reaction process that will take place in the reactor after the drying process is complete.

[0053] In one or more embodiments, the method may further comprise passing a particulate solid, such as a catalyst, to the reactor after the temperature of the reactor is greater than the target temperature. Without intending to be bound by theory, introducing catalyst into the reactor system after the reactor system is heated may allow for greater flexibility in the flow rates for the gaseous fluid used during the heating process. If catalyst is present in the reactor system, the flow rate of the gaseous fluid passing through the reactor system would have to be sufficient to keep the catalyst flowing through the system and maintain certain fluidization regimes within the catalyst system.

[0054] It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present technology, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”

[0055] It should be understood that where a first component is described as “comprising” a second component, it is contemplated that, in some embodiments, the first component “consists of’ or “consists essentially of’ that second component. Additionally, the term “consisting essentially of’ is used in this disclosure to refer to quantitative values that do not materially affect the basic and novel characteristic(s) of the disclosure.

[0056] It should be understood that any two quantitative values assigned to a property may constitute a range of that property, and all combinations of ranges formed from all stated quantitative values of a given property are contemplated in this disclosure.

[0057] The subject matter of the present disclosure has been described in detail and by reference to specific embodiments. It should be understood that any detailed description of a component or feature of an embodiment does not necessarily imply that the component or feature is essential to the particular embodiment or to any other embodiment. Further, it should be apparent to those skilled in the art that various modifications and variations can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

Claims

1. A method for heating a reactor system containing a reactor and a regenerator, comprising: passing a gaseous fluid into the regenerator at a first flow rate; passing a first portion of the gaseous fluid present in the regenerator into the reactor at a second flow rate, wherein the second flow rate is from 50% to 80% of the first flow rate; passing a first portion of the gaseous fluid present in the reactor out of the reactor in an outlet stream of the reactor; passing the first portion of the reactor outlet stream back into the reactor; passing a second portion of the reactor outlet stream outside the reactor system at a third flow rate, wherein the third flow rate is from 10% to 50% of the first flow rate; passing a second portion of the gaseous fluid present in the reactor outside the reactor system at a fourth flow rate, wherein the fourth flow rate is from 10% to 50% of the first flow rate; wherein the temperature of the gaseous fluid passed into the regenerator increases over a certain period of time by 100°C or more.

2. The method according to paragraph 1, wherein the temperature of the regenerator does not exceed the temperature of the reactor by an amount equal to or greater than 100°C.

3. The method according to paragraph 1 or 2, wherein the temperature of the regenerator increases at a rate of 5°C / h to 50°C / h.

4. The method according to any one of paragraphs 1-3, wherein the temperature of the reactor increases at a rate of 5°C / h to 50°C / h.

5. The method according to any one of paragraphs 1-4, in which the reactor outlet stream is passed through a compressor.

6. The method of claim 5, wherein the reactor outlet stream is divided to form a first portion of the reactor outlet stream and a second portion of the reactor outlet stream downstream of the compressor.

7. The method according to any one of paragraphs 1-6, wherein the third flow rate is from 20% to 45% of the first flow rate.

8. The method according to any one of paragraphs 1-7, in which the temperature of the gaseous fluid passed into the regenerator is increased in a heater.

9. The method according to any one of claims 1 to 8, wherein the gaseous fluid medium contains at least 50% by weight of air.

10. The method of any one of paragraphs 1-9, wherein the velocity through the cross-sectional area for the gaseous fluid passed through the reactor is greater than or equal to 1 ft / s.

11. The method of any one of claims 1-10, further comprising passing a second portion of the gaseous fluid present in the regenerator outside the reactor system at a fifth flow rate, wherein the fifth flow rate is from 10% to 50% of the first flow rate.

12. The method according to any one of paragraphs. 1-11, further comprising at least partially opening or at least partially closing one or more valves such that the second flow rate is from 50% to 80% of the first flow rate.

13. The method according to any one of paragraphs. 1-12, further comprising at least partially opening or at least partially closing one or more valves such that the third flow rate is from 10% to 50% of the first flow rate.

14. The method according to any one of paragraphs 1-13, further comprising at least partially opening or at least partially closing one or more valves such that the fourth flow rate is from 10% to 50% of the first flow rate.

15. The method according to any one of paragraphs 1-14, further comprising passing the catalyst into the reactor after the temperature of the reactor exceeds a predetermined temperature, wherein the predetermined temperature is from 200°C to 400°C.